list packages support

[thehesiod]

I'd really like to be able to switch to freight to support multiple versions however two features are missing:

1. removal of package: issue in original repo No way to remove package from a repo? rcrowley/freight#40
2. listing of packages.

In reprepro world I do a reprepro -b CACHE_FOLDER list DISTRIBUTION to list all the packages and then present this via the web server.

can something like that be supported?